Our recent piece, “Death, Taxes, and Reversion to the Mean” 2, aimed to provide context for analysts building financial models by documenting return on invested capital (ROIC) patterns for a large sample of companies. But the report was silent on the question most relevant for investors: Does an understanding of ROIC patterns help with stock picking? This piece addresses that question.
Three main points emerged from the analysis of ROIC patterns. First, analysts need to consider the lessons of history when modeling rather than approaching each model as unique. Analysts should view the experience of a large sample of companies as a rich reference class. Second, the empirical evidence shows ROICs tend to revert to the mean, a level similar to the cost of capital. Randomness plays an important role in the mean-reversion process. Finally, some companies do deliver persistently high or low results beyond what chance would dictate. Unfortunately, pinpointing the causes of persistence is a challenge.
In an efficient market, stock prices are an unbiased estimate of value. Market efficiency does not say that stock prices are always right; it only asserts that prices are not wrong in a systematic way. For this analysis, we combined our data on ROIC patterns with total shareholder returns to see whether there is a consistent way to generate excess returns.